Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Abstract

Provided is an electrophotographic photosensitive member in which the generation of a positive ghost image is suppressed under a low-temperature and low-humidity environment, and the occurrence of cracking is suppressed under a high-temperature and high-humidity environment. Also provided are a process cartridge mounted with the electrophotographic photosensitive member, and an electrophotographic apparatus including the process cartridge. The electrophotographic photosensitive member of the present disclosure is characterized in that an undercoat layer contains aluminum oxide particles and titanium oxide particles at a specific mass ratio.

What is claimed is: 
     
       1. An electrophotographic photosensitive member comprising, in this order:
 (i) a support; 
 (ii) an undercoat layer comprising metal oxide particles (α) and a binder resin (β); and 
 (iii) a photosensitiver layer; 
 the metal oxide particles (α) comprising aluminum oxide particles and titanium oxide particles, the aluminum oxide particles being surface-treated with a silane coupling agent and the titanium oxide particles being surface-treated with a silane coupling agent, wherein 
 1.0≤M α /M β ≤4.0 where M α  is a content of the metal oxide particles (α) and M β  is a content of the binder resin (β) in the undercoat layer, 
 a total of a content of the aluminum oxide particles and a content of the titanium oxide particles in the undercoat layer is 50 mass % or more with respect to the metal oxide particles (α) in the undercoat layer, and 
 0.25≤M Al /M Ti ≤1,000 where M Al  is a content of the aluminum oxide particles and M Ti  is a content of the titanium oxide particles in the undercoat layer. 
 
     
     
       2. The electrophotographic photosensitive member according to  claim 1 , wherein 0.5≤M Al /M Ti ≤10. 
     
     
       3. The electrophotographic photosensitive member according to  claim 2 , wherein the aluminum oxide particles are surface-treated with a compound represented by formula (1) 
       
         
           
           
               
               
           
         
         where R 1  to R 3  independently represent an alkoxy group or an alkyl group, provided that at least two of R 1  to R 3  are alkoxy groups, R 4  represents an alkyl group having n carbon atoms, and n is an integer of 6 to 18, and 
         (X×n) is 10 to 330 where X is M′ Si /M′ Al ×100, M′ Al  is a mass of aluminum atoms in the surface-treated aluminum oxide particles, and M′ Si  is a mass of silicon atoms derived from the compound represented by formula (1). 
       
     
     
       4. The electrophotographic photosensitive member according to  claim 2 , wherein the undercoat layer has a thickness of 0.1 to 10 μm, and
 the binder resin is a urethane resin. 
 
     
     
       5. The electrophotographic photosensitive member according to  claim 3 , wherein the undercoat layer has a thickness of 0.1 to 10 μm, and
 the binder resin is a urethane resin. 
 
     
     
       6. The electrophotographic photosensitive member according to  claim 1 , wherein the aluminum oxide particles are surface-treated with a compound represented by formula (1) 
       
         
           
           
               
               
           
         
         where R 1  to R 3  independently represent an alkoxy group or an alkyl group, provided that at least two of R 1  to R 3  are alkoxy groups, R 4  represents an alkyl group having n carbon atoms, and n is an integer of 6 to 18, and 
         (X×n) is 10 to 330 where X is M′ Si /M′ Al ×100, M′ Al  is a mass of aluminum atoms in the surface-treated aluminum oxide particles, and M′ Si  is a mass of silicon atoms derived from the compound represented by formula (1). 
       
     
     
       7. The electrophotographic photosensitive member according to  claim 6 , wherein the undercoat layer has a thickness of 0.1 to 10 μm, and
 the binder resin is a urethane resin. 
 
     
     
       8. The electrophotographic photosensitive member according to  claim 6 , wherein X×n is 10 to 220. 
     
     
       9. The electrophotographic photosensitive member according to  claim 8 , wherein n is 6 to 12. 
     
     
       10. The electrophotographic photosensitive member according to  claim 9 , wherein the undercoat layer has a thickness of 0.1 to 10 μm, and
 the binder resin is a urethane resin. 
 
     
     
       11. The electrophotographic photosensitive member according to  claim 8 , wherein n is 8. 
     
     
       12. The electrophotographic photosensitive member according to  claim 8 , wherein the undercoat layer has a thickness of 0.1 to 10 μm, and
 the binder resin is a urethane resin. 
 
     
     
       13. The electrophotographic photosensitive member according to  claim 6 , wherein n is 6 to 12. 
     
     
       14. The eleetrophotographic photosensitive member according to  claim 6 , wherein n is 8. 
     
     
       15. The electrophotographic photosensitive member according to  claim 1 , wherein the undercoat layer has a thickness of 0.1 to 10 μm. 
     
     
       16. The electrophotographic photosensitive member according to  claim 1 , wherein the binder resin is a urethane resin. 
     
     
       17. The electrophotographic photosensitive member according to  claim 1 , wherein the titanium oxide particles are surface-treated with N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane. 
     
     
       18. A process cartridge, comprising:
 an electrophotographic photosensitive member; 
 the process cartridge integrally supporting the electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit; and 
 the process cartridge being removably mounted on a main body of an electrophotographic apparatus, wherein 
 the electrophotographic photosensitive member includes (i) a support, (ii) an undercoat layer comprising metal oxide particles (α) and a binder resin (β), and (iii) a photosensitive member in this order, 
 the metal oxide particles (α) comprise aluminum oxide particles and titanium oxide particles, the aluminum oxide particles being surface-treated with a silane coupling agent and the titanium oxide particles being surface-treated with a silane coupling agent, 
 1.0≤M α /M β 4.0 where M α  is a content of the metal oxide particles (α) and M β  is a content of the binder resin (β) in the undercoat layer, 
 a total of a content of the aluminum oxide particles and a content of the titanium oxide particles in the undercoat layer is 50 mass % or more with respect to the metal oxide particles (a) in the undercoat layer, and 
 0.25≤M Al /M Ti ≤1,000 where M Al  is a content of the aluminum oxide particles and M Ti  is a content of the titanium oxide particles in the undercoat layer. 
 
     
     
       19. An electrophotographic apparatus, comprising:
 an electrophotographic photosensitive member; and 
 at least one unit selected from the group consisting of a charging unit, an exposing unit, a developing unit, and a transferring unit, wherein 
 the electrophotographic photosensitive member includes (i) a support, (ii) an undercoat layer comprising metal oxide particles (α) and a binder resin (β), and (iii) photosensitive member in this order, 
 the metal oxide particles (α) comprise aluminum oxide particles and titanium oxide particles, the aluminum oxide particles being surface-treated with a silane coupling agent and the titanium oxide particles being surface-treated with a silane coupling agent, 
 1.0≤M α /M β ≤4.0 where M α  is a content of the metal oxide particles (α) and M β  is a content of the binder resin (β) in the undercoat layer, 
 a total of a content of the aluminum oxide particles and a content of the titanium oxide particles in the undercoat layer is 50 mass % or more with respect to the metal oxide particles (α) in the undercoat layer, and 
 0.25≤M Al /M Ti ≤1,000 where M Al  is a content of the aluminum oxide particles and M Ti  is a content of the titanium oxide particles in the undercoat layer. 
 
     
     
       20. The electrophotographic apparatus according to  claim 19 , wherein the charging unit is a charging roller which is arranged so as to be brought into abutment against the electrophotographic photosensitive member, and which is configured to charge the electrophotographic photosensitive member by applying only a DC voltage thereto.